Nosocomial infection of C. auris in COVID-19 Intensive Care Unit in Türkiye and Phylogenetic Analysis of Isolates

BACKGROUND

The difficulties in the identification of C. auris and the delays in the implementation of infection control precautions contribute to outbreaks. This study analyzed 10 patients with COVID-19 and C. auris candidemia, their characteristic and clinical features and phylogenetic features, and the antifungal susceptibilities of the isolates.

METHOD

C. auris were detected in the COVID-19 ICU of a university hospital between January and August 2021. Identification to species level was performed using MALDI-TOF MS. Antifungal susceptibilities were determined by the Sensititre YeastOne YO10 panel. The isolates were whole genome sequenced to assess genetic relatedness and a phylogenetic tree was drawn including various C. auris clades.

RESULTS

The mean growth time in blood cultures was 38.8 h. C. auris candidemia developed on the average 27th day of ICU admission. All were susceptible to anidulafungin and micafungin, while they were resistant to fluconazole and amphotericin B. Only three isolates were found to be resistant to caspofungin. All patients died. With the WGS method, all isolates were found in a close resemblance to each other in terms of total nucleotide similarity (with a minimum of 96% pairwise alignment). Our isolates showed the closest similarity to South Asian clade (Clade I).

CONCLUSIONS

This study is the first to evaluate the phylogenetic characteristics of C. auris using WGS and to determine antifungal susceptibilities in Türkiye on COVID-19 patients. The mortality rate was very high in patients who have both COVID-19 and C. auris candidemia.

Weaning from mechanical ventilation in intensive care units across 50 countries (WEAN SAFE): a multicentre, prospective, observational cohort study

BACKGROUND

Current management practices and outcomes in weaning from invasive mechanical ventilation are poorly understood. We aimed to describe the epidemiology, management, timings, risk for failure, and outcomes of weaning in patients requiring at least 2 days of invasive mechanical ventilation.

METHODS

WEAN SAFE was an international, multicentre, prospective, observational cohort study done in 481 intensive care units in 50 countries. Eligible participants were older than 16 years, admitted to a participating intensive care unit, and receiving mechanical ventilation for 2 calendar days or longer. We defined weaning initiation as the first attempt to separate a patient from the ventilator, successful weaning as no reintubation or death within 7 days of extubation, and weaning eligibility criteria based on positive end-expiratory pressure, fractional concentration of oxygen in inspired air, and vasopressors. The primary outcome was the proportion of patients successfully weaned at 90 days. Key secondary outcomes included weaning duration, timing of weaning events, factors associated with weaning delay and weaning failure, and hospital outcomes. This study is registered with ClinicalTrials.gov, NCT03255109.

FINDINGS

Between Oct 4, 2017, and June 25, 2018, 10 232 patients were screened for eligibility, of whom 5869 were enrolled. 4523 (77·1%) patients underwent at least one separation attempt and 3817 (65·0%) patients were successfully weaned from ventilation at day 90. 237 (4·0%) patients were transferred before any separation attempt, 153 (2·6%) were transferred after at least one separation attempt and not successfully weaned, and 1662 (28·3%) died while invasively ventilated. The median time from fulfilling weaning eligibility criteria to first separation attempt was 1 day (IQR 0-4), and 1013 (22·4%) patients had a delay in initiating first separation of 5 or more days. Of the 4523 (77·1%) patients with separation attempts, 2927 (64·7%) had a short wean (≤1 day), 457 (10·1%) had intermediate weaning (2-6 days), 433 (9·6%) required prolonged weaning (≥7 days), and 706 (15·6%) had weaning failure. Higher sedation scores were independently associated with delayed initiation of weaning. Delayed initiation of weaning and higher sedation scores were independently associated with weaning failure. 1742 (31·8%) of 5479 patients died in the intensive care unit and 2095 (38·3%) of 5465 patients died in hospital.

INTERPRETATION

In critically ill patients receiving at least 2 days of invasive mechanical ventilation, only 65% were weaned at 90 days. A better understanding of factors that delay the weaning process, such as delays in weaning initiation or excessive sedation levels, might improve weaning success rates.

FUNDING

European Society of Intensive Care Medicine, European Respiratory Society.

A pilot study for treatment of severe COVID-19 pneumonia by aerosolized formulation of convalescent human immune plasma exosomes (ChipEXO™)

This is a single-center prospective, open-label, single arm interventional study to test the safety and efficacy of recently described ChipEXO™ for severe COVID-19 pneumonia. The ChipEXO™ is a natural product derived from convalescent human immune plasma of patients recovered from moderate COVID-19 infection. In September 2021, 13 patients with pending respiratory failure were treated with ChipEXO™ adapted for aerosolized formulation delivered via jet nebulizer. Patients received 1-5x10¹⁰ nano vesicle/5 mL in distilled water twice daily for five days as an add-on to ongoing conventional COVID-19 treatment. The primary endpoint was patient safety and survival over a 28-day follow-up. The secondary endpoint was longitudinal assessment of clinical parameters following ChipEXO™ to evaluate treatment response and gain insights into the pharmacodynamics. ChipEXO™ was tolerated well without any allergic reaction or acute toxicity. The survival rate was 84.6% and 11 out of 13 recovered without any sequel to lungs or other organs. ChipEXO™ treatment was effective immediately as shown in arterial blood gas analyses before and two hours after exosome inhalation. During the 5 days of treatment, there was a sustainable and gradual improvement on oxygenation parameters: i.e. respiratory rate (RR) [20.8% (P < 0.05)], oxygen saturation (SpO₂) [6,7% (P < 0.05)] and partial pressure of oxygen to the fraction of inspired oxygen (PaO₂/FiO₂) [127.9% (P < 0.05)] that correlated with steep decrease in the disease activity scores and inflammatory markers, i.e. the sequential organ failure assessment (SOFA) score (75%, p < 0.05), C-reactive protein (46% p < 0.05), ferritin (58% p = 0.53), D-dimer (28% p=0.46). In conclusion, aerosolized ChipEXO™ showed promising safety and efficacy for life-threatening COVID-19 pneumonia. Further studies on larger patient populations are required to confirm our findings and understand the pathophysiology of improvement toward a new therapeutic agent for the treatment of severe COVID-19 pneumonia.

A pilot study for treatment of severe COVID-19 pneumonia by aerosolized formulation of convalescent human immune plasma exosomes (ChipEXO™)

This is a single-center prospective, open-label, single arm interventional study to test the safety and efficacy of recently described ChipEXO™ for severe COVID-19 pneumonia. The ChipEXO™ is a natural product derived from convalescent human immune plasma of patients recovered from moderate COVID-19 infection. In September 2021, 13 patients with pending respiratory failure were treated with ChipEXO™ adapted for aerosolized formulation delivered via jet nebulizer. Patients received 1-5x1010 nano vesicle/5 mL in distilled water twice daily for five days as an add-on to ongoing conventional COVID-19 treatment. The primary endpoint was patient safety and survival over a 28-day follow-up. The secondary endpoint was longitudinal assessment of clinical parameters following ChipEXO™ to evaluate treatment response and gain insights into the pharmacodynamics. ChipEXO™ was tolerated well without any allergic reaction or acute toxicity. The survival rate was 84.6% and 11 out of 13 recovered without any sequel to lungs or other organs. ChipEXO™ treatment was effective immediately as shown in arterial blood gas analyses before and two hours after exosome inhalation. During the 5 days of treatment, there was a sustainable and gradual improvement on oxygenation parameters: i.e. respiratory rate (RR) [20.8% (P &lt; 0.05)], oxygen saturation (SpO2) [6,7% (P &lt; 0.05)] and partial pressure of oxygen to the fraction of inspired oxygen (PaO2/FiO2) [127.9% (P &lt; 0.05)] that correlated with steep decrease in the disease activity scores and inflammatory markers, i.e. the sequential organ failure assessment (SOFA) score (75%, p &lt; 0.05), C-reactive protein (46% p &lt; 0.05), ferritin (58% p = 0.53), D-dimer (28% p=0.46). In conclusion, aerosolized ChipEXO™ showed promising safety and efficacy for life-threatening COVID-19 pneumonia. Further studies on larger patient populations are required to confirm our findings and understand the pathophysiology of improvement toward a new therapeutic agent for the treatment of severe COVID-19 pneumonia.

A pilot study for treatment of severe COVID-19 pneumonia by aerosolized formulation of convalescent human immune plasma exosomes (ChipEXO™)

This is a single-center prospective, open-label, single arm interventional study to test the safety and efficacy of recently described ChipEXO™ for severe COVID-19 pneumonia. The ChipEXO™ is a natural product derived from convalescent human immune plasma of patients recovered from moderate COVID-19 infection. In September 2021, 13 patients with pending respiratory failure were treated with ChipEXO™ adapted for aerosolized formulation delivered via jet nebulizer. Patients received 1-5x1010 nano vesicle/5 mL in distilled water twice daily for five days as an add-on to ongoing conventional COVID-19 treatment. The primary endpoint was patient safety and survival over a 28-day follow-up. The secondary endpoint was longitudinal assessment of clinical parameters following ChipEXO™ to evaluate treatment response and gain insights into the pharmacodynamics. ChipEXO™ was tolerated well without any allergic reaction or acute toxicity. The survival rate was 84.6% and 11 out of 13 recovered without any sequel to lungs or other organs. ChipEXO™ treatment was effective immediately as shown in arterial blood gas analyses before and two hours after exosome inhalation. During the 5 days of treatment, there was a sustainable and gradual improvement on oxygenation parameters: i.e. respiratory rate (RR) [20.8% (P &lt; 0.05)], oxygen saturation (SpO2) [6,7% (P &lt; 0.05)] and partial pressure of oxygen to the fraction of inspired oxygen (PaO2/FiO2) [127.9% (P &lt; 0.05)] that correlated with steep decrease in the disease activity scores and inflammatory markers, i.e. the sequential organ failure assessment (SOFA) score (75%, p &lt; 0.05), C-reactive protein (46% p &lt; 0.05), ferritin (58% p = 0.53), D-dimer (28% p=0.46). In conclusion, aerosolized ChipEXO™ showed promising safety and efficacy for life-threatening COVID-19 pneumonia. Further studies on larger patient populations are required to confirm our findings and understand the pathophysiology of improvement toward a new therapeutic agent for the treatment of severe COVID-19 pneumonia.

Cytokine Adsorption in Critically Ill COVID-19 Patients, a Case-Control Study

Aim: New coronavirus disease (COVID-19) has become an international emergency. As many of the intensive care unit (ICU) patients with the disease also present multiple organ failure, blood purification techniques might be a good choice in their treatment. In this study we aimed to investigate the role of cytokine removal in COVID-19 patients managed in ICUs. Methods: For this case-control study we have investigated the role of the cytokine removal by means of two resin membranes (HA330 and Mediasorb) in COVID-19 patients managed in ICUs. Particularly, we investigated the overtime variation in clinical severity scores, laboratory variables, and effects on hospital and ICU stay and mortality. Results: Seventy-two patients have been evaluated, of which half constituted Cytokine Filtration (CF) Group, and other half the Case-Control (CC) Group. Mortality was 55.6% and 50% in CF and CC groups, respectively. In the CF Group, there was decrease in C-reactive protein (CRP) and fibrinogen levels measured at the end of cytokine adsorption; lymphocyte count and ratio were increased, whereas neutrophile ratio was decreased. There were no differences between the groups regarding other laboratory variables, SOFA scores and vasopressor uses. Conclusions: We have demonstrated decrease in CRP, fibrinogen and increase in lymphocyte count in the patients having cytokine adsorption, but there was no clinical reflection of these benefits, and no decrease in mortality as well. Even though there is physio-pathologic rationale to use cytokine adsorption techniques for immunomodulation in critically ill COVID-19 patients, it is early to make strong suggestions about their benefits.

Reduction of nosocomial infections in the intensive care unit using an electronic hand hygiene compliance monitoring system

INTRODUCTION

Healthcare-associated infection is an important cause of mortality and morbidity worldwide. Well-regulated infection control and hand hygiene are the most effective methods for preventing healthcare-associated infections. This study evaluated and compared conventional hand hygiene observation and an electronic hand-hygiene recording and reminder system for preventing healthcare-associated infections.

METHODOLOGY

This pre- and post-intervention study, employed an electronic hand-hygiene recording and reminder system for preventing healthcare-associated infections at a tertiary referral center. Healthcare-associated infection surveillance was recorded in an anesthesia and reanimation intensive care unit from April 2016 to August 2016. Hand-hygiene compliance was observed by conventional observation and an electronic recording and reminder system in two consecutive 2-month periods. healthcare-associated infections were calculated as incidence rate ratios.

RESULTS

The rate of healthcare-associated infections in the electronic hand- hygiene recording and reminder system period was significantly decreased compared with that in the conventional hand-hygiene observation period (incidence rate ratio = 0.58; 95% confident interval = 0.33-0.98). Additionally, the rate of central line-associated bloodstream infections and the rate of ventilator-associated pneumonia were lower during the electronic hand hygiene recording and reminder system period (incidence rate ratio= 0.41; 95% confident interval = 0.11-1.30 and incidence rate ratio = 0.67; 95% confident interval = 0.30-1.45, respectively).

CONCLUSIONS

After implementing the electronic hand hygiene recording and reminder system, we observed a significant decrease in healthcare-associated infections and invasive device-associated infections. These results were encouraging and suggested that electronic hand hygiene reminder and recording systems may reduce some types of healthcare-associated infections in healthcare settings.

An outbreak investigation of Burkholderia cepacia infections related with contaminated chlorhexidine mouthwash solution in a tertiary care center in Turkey

BACKGROUND

We report a nosocomial outbreak caused by Burkholderia cepacia that occurred among six patients admitted in the medical and surgical intensive care unit between 04 March 2019 and 02 April 2019 in Istanbul, Turkey.

METHODS

The outbreak investigation was launched on 11 March 2019 five days after the detection of B. cepacia in four different patients. We defined potential reservoirs and started environmental screening. We sampled the liquid solutions used in patient care activities. Pulse-field gel electrophoresis (PFGE) was performed to determine the genetic relatedness of environmental and patient samples.

RESULTS

Burkholderia cepacia was isolated in tracheal aspiration cultures of six patients. Three out of six patients developed healthcare-associated pneumoniae due to B. cepacia. Environmental cultures in the ICUs revealed B. cepacia growth in 2% chlorhexidine-gluconate mouthwash solution that been used in the colonized patients as well as in samples obtained from the unused products. PFGE revealed the patient and a specific batch of chlorhexidine mouthwash solution samples had a 96% similarity.

CONCLUSION

Contamination of medical solutions used in critical patient care could cause outbreaks and should be detected early by infection control teams.

Liver stiffness is associated with disease severity and worse clinical scenarios in coronavirus disease 2019: A prospective transient elastography study

BACKGROUND

Pre-existing chronic liver disease is currently considered a poor prognostic factor for coronavirus disease 2019 (COVID-19). The present study aimed to investigate the association of liver stiffness measurement (LSM) with disease severity and clinical course of COVID-19.

METHODS

We prospectively recruited consecutive hospitalised adult patients with COVID-19 in a 3-month period. Demographic, laboratory, clinical and vibration-controlled transient elastography (VCTE) features were recorded at entry, and all patients were prospectively followed-up. Severe liver fibrosis was defined as an LSM value higher than 9.6 kPA. Multivariate logistic regression analysis was performed to reveal factors associated with disease severity and outcomes.

RESULTS

Out of 98 eligible patients with COVID-19, 12 (12.2%) had severe liver fibrosis. Patients with severe liver fibrosis had higher baseline disease severity (P = .022), more commonly required oxygen treatment at entry (P = .010), and had intensive-care unit (ICU) requirements during the 6 (1-39)-day median follow-up time (P = .017). The presence of severe liver fibrosis was independently associated with disease severity (odds ratio (OR): 7.685, 95% confidence interval (CI): 1.435-41.162, P = .017) and ICU requirement (OR: 46.656, 95% CI: 2.144-1015.090, P = .014). LSM was correlated with alanine aminotransferase levels (P = .005, r: 0.283), but not with other markers of acute hepatic injury or inflammation.

CONCLUSION

Initial VCTE application might help physicians identify patients who are more likely to have severe illness or worse clinical outcomes, in addition to other well-established clinical and laboratory factors. Further multicentre prospective studies are warranted to validate our results.

Evaluation of acute kidney injury with oxidative stress biomarkers and Renal Resistive Index after cardiac surgery

BACKGROUND

We investigated whether cardiopulmonary bypass (CPB) related oxidative stress mediated glycocalyx degradation can cause an increase in renal resistive index (RRI) or postoperative AKI. Additionally, to evaluate whether RRI and early postoperative serum cystatin C levels could improve the prediction sensitivity of acute kidney injury (AKI).

METHODS

Forty-two patients undergoing cardiac surgery were included in this prospective observational study. RRI was measured pre-operatively and in the cardiac intensive care unit. Blood samples were collected for analyzing of cellular injury biomarkers at preoperative and postoperative second hours. We determined areas under the receiver operating characteristic curve (AUC) and odds ratios for postoperative biomarkers and RRI to predict AKI.

RESULTS

While postoperative cystatin C level (AUC: 0.902, 95% CI = 0.79-1.00, p < .001) and RRI (AUC: 0.748, 95% CI = 0.56-0.93, p = .023) have diagnostic and predictive value in the prediction of AKI, we could not identify any relation between products of oxidative stress and the glycocalyx degradation and AKI.

CONCLUSION

These data suggest that CPB leads to structural and oxidative changes at the protein level and the integrity of glycocalyx is disturbing, but these changes are not specific to kidney injury. Our data suggest that serum cystatin C level and RRI could be used as an early biomarker for postoperative AKI after cardiac surgery.

Immunomodulatory and Tissue-preserving Effects of Human Dental Follicle Stem Cells in a Rat Cecal Ligation and Perforation Sepsis Model

BACKGROUND

Mesenchymal stem cells may be used for the treatment of sepsis. Dental follicle stem cells (DFSCs) are easily accessible but have not been studied in vivo or in clinical trials in sepsis models.

AIM OF THE STUDY

We aim to elucidate DFSC effects on host immunological functions in a rat cecal ligation and perforation (CLP) sepsis model.

METHODS

Adult male rats were categorized into group 1 (sham procedure SP), group 2 (SP + 1 × 10⁶ DFSCs administered 0 h after SP), group 3 (CLP + saline), group 4 (CLP + 1 × 10⁶ DFSCs administered 0 h after CLP), and group 5 (CLP + 1 × 10⁶ DFSCs administered 4 h after CLP). Green fluorescent protein-labeled cells were used for imaging. Histopathological examination of ileal tissues was performed.

RESULTS

A significant increase in the percentage of CD4+/CD25+/Foxp3+ Treg cells in groups 4 and 5 occurred compared with that in group 3. No significant changes in CD3+/CD4+ helper T-cells and CD3+/CD8+ cytotoxic T-cells were observed. Treatment with DFSCs at 4 h significantly decreased the level of TNF-α compared with that in group 3. No significant changes in IL-10 levels and lymphocyte proliferation suppression were observed. During histopathological examination, no high scoring (Chiu scores: 3 or 4) rats were observed in the curative treatment group (group 5).

CONCLUSIONS

Treatment with DFSC after 4 h of sepsis induction downregulates tissue inflammatory responses by decreasing TNF-α levels and increasing Treg cell ratio. This also has a protective effect on intestinal tissues during sepsis.

The initial resuscitation of septic shock

Septic shock is the most severe form of sepsis, characterized by (a) persistent hypotension despite fluid resuscitation and (b) the presence of tissue hypoperfusion. Delays in the diagnosis and initiation of treatment of septic shock is associated with increasing risk for mortality. Early and effective fluid resuscitation and vasopressor administration play a crucial role in maintaining tissue perfusion in septic shock patients. A low diastolic arterial pressure (DAP) correlates with severity of arteriolar vasodilation, compromises left ventricle oxygen supply and can be used for identifying septic shock patients that would potentially benefit from earlier vasopressor therapy. Controversy currently exists as to the balance of fluids and vasopressors to maintain target mean arterial pressure. The aim of this article is to review the rationale for fluid resuscitation and vasopressor therapy and the importance of both mean and diastolic blood pressure during the initial resuscitation of the septic shock. We relate our personal prescription of balancing fluids and vasopressors in the resuscitation of septic shock.

A new scoring system for early diagnosis of ventilator-associated pneumonia: LUPPIS

INTRODUCTION

The Clinical Pulmonary Infection Score (CPIS) based on chest X-ray has been developed to facilitate clinical diagnosis of ventilator-associated pneumonia (VAP); however, this scoring system has a low diagnostic performance. We developed the Lung Ultrasound and Pentraxin-3 Pulmonary Infection Score (LUPPIS) for early diagnosis of VAP and evaluated the performance of this new scoring system.

MATERIAL AND METHODS

In a prospective study of 78 patients with suspected VAP, we assessed the detection accuracy of LUPPIS for pneumonia in adult patients. We also evaluated the diagnostic performance of pentraxin-3 (PTX-3) findings of infection. On the day of the study, lung ultrasound was performed, PTX-3 levels were determined, and an endotracheal aspirate was obtained for Gram staining and culture.

RESULTS

No significant differences were found between groups with respect to age, mechanical ventilation time, APACHE II score, or SOFA score (p > 0.05). Procalcitonin and PTX-3 levels were significantly higher in the VAP (+) group (p < 0.001 and p < 0.001, respectively). The threshold for LUPPIS in differentiating VAP (+) patients from VAP (-) patients was > 7. In predicting VAP, LUPPIS > 7 (sensitivity of 84%, specificity of 87.7%) was superior to CPIS > 6 (sensitivity of 40.1%, specificity of 84.5%).

CONCLUSIONS

LUPPIS appears to provide better results in the prediction of VAP compared to CPIS, and the importance of lung ultrasound and PTX-3 is emphasized, which is a distinctive property of LUPPIS.

Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine: Brussels, Belgium. 15-18 March 2016

[This corrects the article DOI: 10.1186/s13054-016-1208-6.].

Vitamin D level is associated with mortality predictors in ventilator-associated pneumonia caused by Acinetobacter baumannii

INTRODUCTION

Vitamin D plays a role in host defense and is known to be associated with mortality in patients in the intensive care unit (ICU). We aimed to evaluate the relationships between vitamin D levels and predictors of mortality in patients with ventilator-associated pneumonia (VAP) caused by extensively drug-resistant Acinetobacter baumanii (XDR A. baumanii).

METHODOLOGY

A retrospective single-center study was conducted in an 18-bed adult ICU of a teaching hospital, including all patients with VAP due to XDR A. baumanii. Levels of 25(OH)D, procalcitonin (PCT), C-reactive protein (CRP), n-terminal pro-BNP (NT-proBNP), as well as clinical scores (Sequential Organ Failure Assessment [SOFA], Acute Physiology And Chronic Health Evaluation [APACHE II], Clinical Pulmonary Infection Score [CPIS) were recorded.

RESULTS

Forty-for patients were studied over six months. All patients had vitamin D deficiency. The 28-day mortality in patients with 25(OH)D levels ≤ 10 ng/mL was higher than in patients with 25(OH)D > 10ng/mL (p = 0.001). The fourth- and seventh-day SOFA scores (p= 0.04 and p= 0.001) and first- and fourth-day procalcitonin levels (p = 0.03 and p = 0.004) were higher in patients with 25(OH)D levels ≤ 10 ng/mL. The clinical scores (SOFA, CPIS, and CEPPIS) and biomarkers (NT-proBNP, PCT) were negatively correlated with 25(OH)D levels in all study groups.

CONCLUSIONS

Severe vitamin D deficiency was associated with adverse outcome in VAP due to XDR A. baumanii. Vitamin D levels may be a prognostic predictor of VAP. It is also important to evaluate the effect of rapid vitamin D replacement on mortality.

The diagnostic value of soluble urokinase plasminogen activator receptor compared with C-reactive protein and procalcitonin in children with febrile neutropenia

The aim of the present study was to determine the diagnostic value of soluble urokinase plasminogen activator receptor (suPAR) in pediatric patients with febrile neutropenia. A prospective case-control study was performed. Patients included 29 children with febrile neutropenia (FN) and 27 control subjects without any infection or immunosuppressive condition. Blood samples were obtained on the day of admission and on the 4th to 7th days of the hospital stay. The median (minimum-maximum) serum levels of suPAR obtained on the first day of the admission were 2.08 (0.93-9.42) and 2.22 (1.08-5.13) ng/mL for the FN group and the control group, respectively. The median serum levels of suPAR in the FN and control groups were not significantly different (P = .053). The mean serum suPAR level was significantly higher in nonsurvivors than in survivors in the FN group (P < .05). In the FN group, the area under the receiver operating characteristics curve (AUCROC) for suPAR was 0.546, but no optimum cutoff value, sensitivity, specificity, negative predictive value (NPV), or positive predictive value (PPV) was obtained. We conclude that suPAR is not useful as a diagnostic biomarker in children with febrile neutropenia; however, persistent high serum suPAR level may predict mortality in FN in children.

Involvement of Rho kinase (ROCK) in sepsis-induced acute lung injury

Indirect acute lung injury is associated with high morbidity and mortality. We investigated the link between Rho kinase (ROCK) activation and apoptotic cell death in sepsis induced acute lung injury. This hypothesis was tested by administering a specific, selective inhibitor of ROCK (Y-27632) to rats subjected to cecal ligation and puncture (CLP). Rats were randomly divided into 4 groups as; sham-operated, sham + Y-27632, CLP and CLP + Y-27632. Twenty-four hours later, each experiment was terminated and lungs analyzed. Histopathology was assessed by hematoxylin-eosin staining and the presence of apoptosis was evaluated through the TUNEL assay. Pulmonary activity of caspase 3 and ROCK 1 & 2 were measured by western blot. Interstitial edema, severely damaged pulmonary architecture with massive infiltration of the inflammatory cells and an increase in lung tissue TBARS levels as well as 3-NT to total tyrosine ratios were observed in untreated CLP animals. Pretreatment of animals with Y-27632, reduced lung injury in the CLP induced septic rats in each of these parameters of lung injury (p<0.05). Western immunoblot revealed active caspase cleavage and increased expression of active fragment of ROCK 1 & 2 in the CLP group. TUNEL assay showed an increase in percentage of apoptotic cells when comparing the CLP group with the CLP + Y-27632 group. These results suggest an important role of Rho kinase in sepsis induced lung injury by a mechanism that might be related to oxidative and/or nitrosative stress mediated caspase cleavage leading to apoptosis.

The correlation between reactive oxygen species and histopathology of the liver, gut, and kidneys in animals with elevated intra-abdominal pressure

BACKGROUND

Clinical and experimental studies have shown that the laparoscopic procedure provides a typical model of ischemia-reperfusion injury in the organs by oxygen-derived free radicals. A pneumoperitoneum produces ischemia during insufflation and reperfusion during desufflation. The aim of this study was to assess the causative role of free radical-mediated reactions in tissue damage under different intra-abdominal insufflation pressures.

MATERIALS AND METHODS

Thirty five mature New Zealand white rabbits were assigned to three groups of 10 animals. In groups 1, 2, and 3, the designated pressures of 10, 15, and 20 mm Hg, respectively. The remaining 5 animals underwent laparotomy, using a 10-cm midline incision taken as group 4 (control). Blood samples were collected before (0 minutes) and at the end of the procedure (60 minutes). After the collection of the last blood samples, all animals were sacrificed and the samples from the liver, kidney, and gut were obtained for histologic evaluation and also measurements of tissue malondialdehyde (MDA) levels.

RESULTS

The nitric oxide levels were not changed in groups 1 and 2, but increased significantly in group 3. Tissue MDA levels were significantly higher in groups 1 and 2 than groups 3 and 4. Histopathologic examination of the kidney revealed some findings of reversible hypoxic cell injury, including acute cellular swelling, vascular congestion, and some early findings of irreversible injury, such as lysis of the cytoplasmic membrane in all groups and focal parancymal bleeding area in only group 3 as a consequence of increased pressure. Liver histology revealed cellular swelling and karyorhexis in hepatocytes in group 1, whereas only congestion and sinusoidal dilatation was observed in groups 2 and 3.

CONCLUSION

Our experimental study showed that abdominal insufflation causes ischemia and free radical production, which seems responsible for the cell damage that occured during laparoscopic surgery.

Bench-to-bedside review: nitric oxide in critical illness--update 2008

Nitric oxide (NO) is a unique and nearly ubiquitous molecule that is widely utilized as a signaling molecule in cells throughout the body. NO is highly diffusible, labile, and multiply reactive, suiting it well for its role as an important regulator of a number of diverse biologic processes, including vascular tone and permeability, platelet adhesion, neurotransmission, and mitochondrial respiration. NO can protect cells against antioxidant injury, can inhibit leukocyte adhesion, and can participate in antimicrobial defense, but can also have deleterious effects, including inhibition of enzyme function, promotion of DNA damage, and activation of inflammatory processes. This molecule's chemistry dictates its biologic activity, which can be both direct and indirect. In addition, NO has bimodal effects in a number of cells, maintaining homeostasis at low doses, and participating in pathophysiology in others. Perturbation of NO regulation is involved in the most important and prevalent disease processes in critical care units, including sepsis, acute lung injury, and multiple organ failure. Given that NO is ubiquitous, highly diffusible, and promiscuously reactive, its regulation is complex. The NO concentration, kinetics, and localization, both inside and outside the cell, are clearly crucial factors. In the present update we review a selection of studies that have yielded important information on these complex but important issues. Interpretation of these and other studies aimed at elucidating physiologic and pathophysiologic roles of NO must take this complexity into account. A full review of the role of NO in these diseases is beyond the scope of the current manuscript; the present article will focus on recent advances in understanding the complex role of NO in health and disease.

EFFECTS OFN-ACETYLCYSTEINE ON OXIDANT-ANTIOXIDANT BALANCE IN OLEIC ACID–INDUCED LUNG INJURY

The antioxidant and anti-inflammatory properties of N-acetylcysteine has been documented in many experimental lung injury models. Because intravenous injection of oleic acid induces histopathologic changes similar to those seen in human acute lung injury or acute respiratory distress syndrome, the authors evaluated the effects of N-acetylcysteine (NAC) on oxidative stress and lung damage in an oleic acid (OA)-induced lung injury model. Thirty-five rats were divided into 5 groups as sham, NAC, OA, pre-OA-NAC, and post-OA-NAC. Lung damage was induced by intravenous administration of oleic acid. Pre-OA-NACgroup received intravenous (IV) N-acetylcysteine 15 minutes before oleic acid infusion and post-OA-NAC group received IV N-acetylcysteine 2 hours after oleic acid infusion. In both of the N-acetylcysteine treatment groups, blood and tissue samples were collected 4 hours after oleic acid infusion, independent from the time of N-acetylcysteine infusion. In other groups, blood and tissue samples were collected 4 hours after ethanol, NAC, or OA infusions. Serum myeloperoxidase activity, total antioxidant capacity, malondialdehyde levels, and lung tissue Na+ - K+ ATPase activity were measured and light microscopic analyses of lung specimens were performed. The administration of N-acetylcysteine significantly restored Na+ - K+ ATPase activity and total antioxidant capacity levels and ameliorated lung architecture. N-acetylcysteine has been shown to have some attenuating effects in experimental animal studies. However, further investigations are necessary to suggest N-acetylcysteine as a treatment agent in critically ill patients with lung injury.

Assessment of asymmetric lung disease in intensive care unit patients using vibration response imaging

BACKGROUND

Vibration response imaging (VRI) is a computer-based technology that creates a visual dynamic two-dimensional image of distribution of vibration within the lung during the respiratory process. The acoustic signals, recorded from 36 posteriorly positioned surface skin sensors, are transferred to a hardware board where several stages of filtering are applied to select a specific frequency band. The filtered output signal frequencies are presented as a gray-scale coded dynamic image, consisting of a series of 0.17 s frames, and as a table featuring the percentage contribution of each lung to the total vibration signal.

METHODS

We describe the VRI technology in detail and examine images obtained from consecutive intensive care unit (ICU) patients with one diseased lung on chest radiograph. ICU patients with normal chest radiographs are presented as controls. Analysis of the image was performed by comparing the weighted pixel count analysis from both lungs. In this method, the pixels in the image were assigned values based on their grayscale color with the darker pixels assigned higher values.

RESULTS

In patients with normal chest radiographs, the right and left lungs developed similarly in dynamic VRI images, and the percent lung vibrations from both sides were comparable (53%+/-12% and 47%+/-12%, respectively). In ICU patients with asymmetric lung disease, however, the percent lung vibrations from the diseased and nondiseased lungs were 27%+/-23% and 73%+/-23%, respectively (P<0.001). In patients with asymmetric lung disease (one lung has moderate to severe disease and the other appears normal or close to normal as per chest radiograph), the diseased lung usually appeared in VRI as irregular, smaller, and lighter in color (reduced vibration signal) when compared to the nonaffected lung. The weighted pixel count from diseased and nondiseased lungs were 33%+/-21% and 67%+/-21%, respectively (P < 0.003).

CONCLUSION

The VRI technology may provide a radiation-free method for identifying and tracking of asymmetric lung parenchymal processes.

Resuscitating the microcirculation in sepsis: the central role of nitric oxide, emerging concepts for novel therapies, and challenges for clinical trials

Microcirculatory dysfunction is a critical element of the pathogenesis of severe sepsis and septic shock. In this Bench-to-Bedside review, we present: 1) the central role of the microcirculation in the pathophysiology of sepsis; 2) new translational research techniques of in vivo video microscopy for assessment of microcirculatory flow in human subjects; 3) clinical investigations that reported associations between microcirculatory dysfunction and outcome in septic patients; 4) the potential role of novel agents to "rescue" the microcirculation in sepsis; 5) current challenges facing this emerging field of clinical investigation; and 6) a framework for the design of future clinical trials aimed to determine the impact of novel agents on microcirculatory flow and organ failure in patients with sepsis. We specifically focus this review on the central role and vital importance of the nitric oxide (NO) molecule in maintaining microcirculatory homeostasis and patency, especially when the microcirculation sustains an insult (as with sepsis). We also present the scientific rationale for clinical trials of exogenous NO administration to treat microcirculatory dysfunction and augment microcirculatory blood flow in early sepsis therapy.

Left ventricular endocardial pacing: a transarterial approach

INTRODUCTION

We tested the feasibility of a new technique of direct left ventricular endocardial lead placement across the aortic valve in a chronic (six month) pig model. The potential for aortic valve damage, systemic embolization, and pacing lead maturation and function within the left ventricle are unknown.

METHODS

Ten minipigs were successfully implanted with a transaortic left ventricular lead (Medtronic CapSureFix, Minneapolis, MN, USA) placed in the left ventricular apex via the carotid artery. Each pig received either a polyurethane (n = 5) or silicone (n = 5) lead. Post implant each pig received clopidogrel and aspirin for seven days. After six months all surviving pigs underwent thorough necropsy.

RESULTS

Each pig had adequate sensing (12.1 +/- 4 mV) and pacing thresholds (0.79 +/- 0.2 @ 0.5 V) at implant. Postoperatively two pigs died of a respiratory illness. One pig died postoperatively due to sepsis. At the six-month follow-up, all surviving pigs (n = 7) were in a healthy state. Of the pigs without dislodgement (n = 5) there was adequate sensing, but a rise in pacing thresholds. Echocardiography revealed a normal ejection fraction and only trace to mild aortic insufficiency in all pigs. Of the seven surviving pigs there were no thromboembolic events noted. One silicone lead was noted to have thrombosis along the lead screw and shaft.

CONCLUSION

Direct transaortic placement of a left ventricular lead is feasible. After six months, there was no significant aortic regurgitation and no evidence of thromboembolism despite no anticoagulation. Lead function was acceptable and only one silicone lead (and no polyurethane lead) was noted to have significant thrombosis.

Current treatment of severe sepsis

The treatment of severe sepsis includes three essential principles: eradication of the inciting infection using source control measures and empiric antibiotics, hemodynamic resuscitation of hypoperfusion to avoid acute life-threatening organ dysfunction, and sustained support of organ system dysfunction using interventions that minimize organ injury. Therapy can be divided into immediate steps taken to stabilize the patient, followed by more definitive therapeutic intervention. The evidence for best clinical practice for resuscitation, management of infection, and intensive care unit supportive care has recently been synthesized by the Surviving Sepsis Campaign and published as evidence-based guidelines for the management of severe sepsis and septic shock.

Advances in pathogenesis and management of sepsis

PURPOSE OF REVIEW

The rationale for therapeutic targets in sepsis has arisen from the concept of pathogenesis. This review focuses on recent advances in pathogenesis of sepsis that can aid in management of sepsis patients.

RECENT FINDINGS

Cellular survival in sepsis is related to the magnitude of the stimulus, the stage of the cell cycle and the type of microbe. While phenotypic modification of the endothelium (procoagulant and proadhesive properties, increased endothelial permeability, endothelial apoptosis and changes in vasomotor properties) leads to vasoplegia as a direct correlate to septic shock mortality, phenotypic changes in the epithelium cause activation of the virulence of the opportunistic pathogens and loss of mucosal barrier function, the latter causing a vicious circle in severe sepsis. Early identification of sepsis with protocolized screening, triggering evidence-based protocolized care, is anticipated to reduce sepsis morbidity and mortality. Current treatment of sepsis includes early antibiotic therapy, early aggressive goal-directed resuscitation targeting tissue hypoperfusion, steroids (for refractory shock), activated protein C (for high risk of death) and maintaining support of organ systems.

SUMMARY

A better understanding of pathogenesis of sepsis has led to specific proven management tools that are likely to improve clinical outcome once incorporated into protocolized care.

Regional distribution of acoustic-based lung vibration as a function of mechanical ventilation mode

Introduction

There are several ventilator modes that are used for maintenance mechanical ventilation but no conclusive evidence that one mode of ventilation is better than another. Vibration response imaging is a novel bedside imaging technique that displays vibration energy of lung sounds generated during the respiratory cycle as a real-time structural and functional image of the respiration process. In this study, we objectively evaluated the differences in regional lung vibration during different modes of mechanical ventilation by means of this new technology.

Methods

Vibration response imaging was performed on 38 patients on assist volume control, assist pressure control, and pressure support modes of mechanical ventilation with constant tidal volumes. Images and vibration intensities of three lung regions at maximal inspiration were analyzed.

Results

There was a significant increase in overall geographical area (p < 0.001) and vibration intensity (p < 0.02) in pressure control and pressure support (greatest in pressure support), compared to volume control, when each patient served as his or her own control while targeting the same tidal volume in each mode. This increase in geographical area and vibration intensity occurred primarily in the lower lung regions. The relative percentage increases were 28.5% from volume control to pressure support and 18.8% from volume control to pressure control (p < 0.05). Concomitantly, the areas of the image in the middle lung regions decreased by 3.6% from volume control to pressure support and by 3.7% from volume control to pressure control (p < 0.05). In addition, analysis of regional vibration intensity showed a 35.5% relative percentage increase in the lower region with pressure support versus volume control (p < 0.05).

Conclusion

Pressure support and (to a lesser extent) pressure control modes cause a shift of vibration toward lower lung regions compared to volume control when tidal volumes are held constant. Better patient synchronization with the ventilator, greater downward movement of the diaphragm, and decelerating flow waveform are potential physiologic explanations for the redistribution of vibration energy to lower lung regions in pressure-targeted modes of mechanical ventilation.

Could adding magnesium as adjuvant to ropivacaine in caudal anaesthesia improve postoperative pain control?

Recently, most studies reported magnesium as a N-methyl-D-aspartate receptor antagonist and its analgesic and perioperative anaesthetic effects have been discussed with central desensitization pathway. We investigated the effects of caudal ropivacaine plus magnesium and compared with ropivacaine alone on postoperative analgesia requirements. After hospital ethic committee's consent, 60 patients (ASA I-II, 2-10 years old) who had lower abdominal or penoscrotal surgery were enrolled in the study. After general anaesthesia induction, caudal blockage was applied. Patients were randomly assigned in two groups. Ropivacaine 0.25% was administered to Group R (n=37), ropivacaine 0.25% plus 50 mg magnesium to Group RM (n=23) in 0.5 ml kg-1 volume. Postoperative analgesia level was recorded at 15 min and 1, 2, 3, 4, 6 h by using Paediatric Objective Pain Scale (POPS) and The Children's Hospital of Eastern Ontoria Pain Scale (CHEOPS). Postoperative motor blocks were evaluated with Modified Bromage Motor Block Scale. According to demographic characteristics, there were no significant differences between the two groups (P>0.05). POPS, CHEOPS, Bromage Motor Scales, analgesia duration and adverse effects were similar in Group R and Group RM. It has been shown that addition of magnesium as an adjuvant agent to local anaesthetics for caudal analgesia has no effect on postoperative pain and analgesic need.

Guidelines for severe infections: are they useful?

PURPOSE OF REVIEW

The large variability in clinical practice plus the increasing awareness that certain processes of care are associated with improved medical outcomes has led to the development of clinical practice guidelines in serious infection. The evolution of guidelines and their impact on delivery of care in severe infection is reviewed.

RECENT FINDINGS

Guidelines development has centered around community- and hospital-acquired pneumonia as well as sepsis. The Institute of Healthcare Improvement has emerged as an international leader in changing healthcare professional behavior to be consistent with clinical recommendations in infection-related morbidity. These educational programs are designed to increase awareness of guidelines recommendations and to optimize their implementation. Change bundles are selected sets of interventions or processes distilled from evidence-based practice guidelines that are likely to improve outcome. As new evidence is published, and as experts ponder how the guidelines should best be expressed in the bundles, the bundles will be adapted to optimize their utility.

SUMMARY

The change bundle approach to performance improvement (guidelines-based) is the key to change in practice. The Surviving Sepsis Campaign/Institute of Healthcare Improvement sepsis change bundles are an excellent example of progress along these lines.